Using a remote control, Jet Propulsion Laboratory engineers move the All-Terrain, Hex-Limbed, Extra-Terrestrial Explorer (ATHLETE) at the Hahamongna Watershed Park in Pasadena on Thursday, July 29, 2010.

Using a remote control, Jet Propulsion Laboratory engineers move the All-Terrain, Hex-Limbed, Extra-Terrestrial Explorer (ATHLETE) at the Hahamongna Watershed Park in Pasadena on Thursday, July 29, 2010. (Raul Roa/Staff photographer)

Proposed cuts to NASA’s budget would drastically scale back the agency’s efforts to explore Mars and likely lead to hundreds of lay-offs at the Jet Propulsion Laboratory in La Cañada Flintridge, officials say.

Included in the more than $17.7-billion budget proposed for the space agency in 2013 is a $300-million reduction in planetary science funding that would hit JPL particularly hard.

The cuts eliminate two future joint U.S.-European Mars missions that would have been managed by JPL, eliminating positions for many of the scientists and engineers who built and launched NASA’s celebrated Mars rovers.

“If nothing changes in the budget, the impact on us will be a few hundred workers next fiscal year,” said JPL Legislative Affairs Manager Rich O’Toole.

The agency’s fiscal year begins in October.

JPL’s Curiosity rover is expected to reach the Red Planet on Aug. 5. Touchdown will conclude the roles of many on the Curiosity team, who would have gone on to participate in the future Mars missions slashed under the new budget, O’Toole said.

The loss of hundreds of workers would be the second massive round of layoffs at the La Cañada Flintridge laboratory in two years.

JPL suffered a direct $50-million cut in its 2012 budget, prompting preemptive layoffs of 247 employees in February and March of last year, many of those in administrative support positions. Nearly five dozen JPL workers retired in 2011 and were not replaced.

The proposed 2013 NASA budget, announced Monday by NASA Administrator Charles Bolden, is $60 million less than this year’s budget.

Rep. Adam Schiff (D-Burbank) has vowed to fight the cuts, saying funding reductions should be spread out more evenly among NASA’s many scientific priorities.

“Planetary science is an area where we have always excelled as a nation, being able to do things no one else can. This is a leadership role we should not walk away from,” Schiff said. “We already have to go to the Russians to get a ride to the space station, and it would be a sad state if we’re superseded by the Europeans in planetary exploration. It’s a defeatist view of what America is capable of, and not one that I share.”

Bolden is expected to visit JPL on Feb. 22 and has asked to speak with the Mars Science Laboratory team during the trip, said JPL spokeswoman Veronica McGregor.

O’Toole said he expects Bolden to discuss greater collaboration, rather than competition, among NASA departments.

“We are going to work very hard with NASA to preserve the skills necessary for future Mars missions.…If that includes landing on Mars, [JPL’s] skills become very important for that,” he said.

Before budget cuts were announced, JPL and the European Space Agency planned to launch Mars missions in 2016 and 2018 that would continue the search for signs of life and prepare soil samples for possible return to Earth.

Bill Nye, chief executive of the Pasadena-based Planetary Society, said scrapping the missions would be a generational setback for America’s planetary science program.

“The march toward looking for signs of life on Mars, you’re never going to be able to get it back on track, at least not in the coming two decades,” he said. “The rocket scientists, engineers, technicians — the only people in the world who are able to do this — will have to go find different work. Once you lose that ability, you don’t just get it back.”